Genetic organisation of the type 3 fimbriae (mrk) gene cluster. Physical map of the mrk gene cluster and flanking regions from K. pneumoniae MGH78578, plasmid pMAS2027 (E. coli), plasmid pOLA52 (E. coli), plasmid pIA565 (K. pneumoniae), E. coli ECOR28, C. freundii M46, K. oxytoca M126, and C. koseri ATCC BAA895. The mrk genes are indicated in blue and include mrkE (putative regulatory gene), mrkA (major subunit encoding gene), mrkB (chaperone encoding gene), mrkC (usher encoding gene), mrkD (adhesin encoding gene) and mrkF (putative minor subunit encoding gene). ORFs encoding putative transposable elements (yellow) and hypothetical proteins (grey) are indicated. The gene indicated in red (labelled cko_00966 and kpn_03274 in the genomes of C. koseri ATCC BAA895 and K. pneumoniae MGH78578, respectively) encodes a hypothetical protein containing a central EAL domain and was present downstream of mrkF in 29 strains. Sequence information outside the mrk cluster is not known for K. pneumoniae pIA565. Arrows indicate the direction of transcription for each gene.
Ong et al. BMC Microbiology 2010 10:183 doi:10.1186/1471-2180-10-183